The Dow Jones Industrial average opened down over half a per cent at 16,101.35, while the tech heavy Nasdaq began the day down by one and a half per cent at 4,290.71.

The S&P 500 was trading down one per cent at 1,862.31 at the open.

In premarket trading US stock futures pointed sharply lower, as investors digest lower than expected economic numbers from China and nervousness builds over Federal Reserve chair Janet Yellen's testimony to Congress over the state of the US economy on Wednesday.